1. Field of the Invention
The present invention relates to a substrate holding and rotating apparatus for holding and rotating a substrate. Examples of the substrate to be held include a semiconductor wafer, a liquid-crystal-display-device substrate, a plasma-display substrate, an optical-disk substrate, a magnetic-disk substrate, a photomagnetic-disk substrate, a photomask substrate and the like.
2. Description of Related Art
For example, in a semiconductor device production line, there is used a substrate processing apparatus for processing a substrate with a treating liquid. Examples of the substrate processing apparatus include a batch-type apparatus in which a plurality of substrates are collectively processed as immersed in a treating liquid and a sheet-feed type apparatus in which substrates are processed one by one. A substrate processing apparatus of the sheet-feed type has, for example, a spin chuck for rotating a substrate as substantially horizontally held and a treating liquid nozzle for supplying a treating liquid to a substrate which is under rotation as held by the spin chuck.
The spin chuck has a rotary shaft disposed in a perpendicular direction, a spin base substantially horizontally attached to the upper end of the rotary shaft, a plurality of chuck pins attached to the spin base, and an interlocking link mechanism for interlocking the opening/closing operations of the plurality of chuck pins (See Japanese Patent Laid-Open Publication No. 2003-39007). The plurality of chuck pins are displaceable between holding positions where the chuck pins come in contact with the peripheral edge portion of the substrate, and retreat positions where the chuck pins retreat outwardly from the holding positions. The interlocking link mechanism is connected to a coiled spring for biasing the chuck pins to the holding positions, and has a release lever for moving the chuck pins to the retreat positions against the biasing force of the coiled spring.
The spin chuck is housed in a processing cup. Disposed outside of the processing cup is a release claw for releasing the substrate holding state provided by the chuck pins. At the time of delivery of a substrate to and from the spin chuck, the release claw is operated to operate the release lever to release the substrate holding state provided by the chuck pins.
More specifically, after moved to a position in the vicinity of the spin chuck from the standby position outside of the processing cup, the release claw actuates the release lever to release the holding of the substrate by the chuck pins. Under such a condition, a substrate delivery robot carries out a treated substrate from the spin chuck and carries in an untreated substrate to the spin chuck. Thereafter, the release claw is retreated, causing the substrate to be held by the chuck pins. When the release claw is further moved and returned to the standby position outside of the processing cup, the spin base starts rotating and the feed of a treating liquid also starts.
To securely actuate the release lever by the release claw, it is required to separately dispose a rotation locking mechanism for preventing the spin base from rotating before the holding of a substrate by the chuck pins is released. This disadvantageously not only complicates the arrangement but also requires more space inside of the apparatus and also makes the control complicated.
Further, the release claw has to be moved to a position in the vicinity of the spin chuck from the standby position outside of the processing cup, and thereafter to be returned to the standby position. This takes much time. Accordingly, this takes time for replacement of a substrate to be processed, resulting in reduction in the processing ability of the substrate processing apparatus. Further, before the release claw is operated, it is required not only to operate the rotation locking mechanism but also to make sure of the operation of the rotation locking mechanism. This causes the substrate processing ability to be further lowered.